Tuning-pin.



M. L. SEVERY & W. L. FLINT.

TUNING PIN.

APPLICATION FILED OCT. I1, 1913.

1 ,232,862, Patented July 10, 1917.

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UNITED STATES PATENT OFFICE,

MELVIN L. SEVERY, OF ARLINGTON HEIGHTS, AND WILLIAM L. FLINT, OF VJIN'IliIR-GP, MASSACHUSETTS, ASSIGNORS, BY MESNE ASSIGNMENTS, TO SAID SEVEBY.

TUNINGPIN.

Application filed October 11, 1913.

To all whom it may concern:

Be it known that we, Mnnvix L. Snvnny, of Arlington Heights, in the county of Middlesex and State of hlassachusetts, and VIL- LrAn L. FLINT, of W'inthrop, in the county of Suffolk and State of Massachusetts,have invented certain new and useful Improvements in Tuning-Pins, of which the following is a specification.

This invention relates to an improvement in tuning pins for pianos and analogous stringed musical instruments and provides an improved tuning mechanism intended to take the place of the customary wrest pins. The invention involves the use of a plurality of axially adjustable threaded pins, one for each string in the instrument and each axially alined with its corresponding string. These pins are mounted in holes in a flange, preferably integral with the plate, and are adjusted to vary the tension on their corresponding strings by means of nuts threaded upon them. To prevent the turning of the pins during the adjustment, they are formed with flattened portions on their sides and each pair of adjacent pins is en gaged by a slotted washer so that the pins of each pair are locked by such washer against rotation. While a single washer might be used, better results are secured by using two washers for each pair of pins. Each washer is formed with an aperture adapted to fit one pin closely and wit-h an elongated slot to it the flattened sides of the other pin, The two washers are reversely arranged so that each pin is closely fitted by one washer and is held against turning by the engagement of this washer with the other pin. In this way the cost of forming the holes in the flange, is minimixed, as these holes may be round and somewhat larger than the pins and need not be located with extreme accuracy, the washer structure serving to permit centering of the pins in the holes as well as to lock them against rotation as will hereafter be more fully explained.

The invention will be clearly understood from an inspection of the accompanying drawings, in which:

Figure 1 is a sectional side elevation of the preferred embodiment of the invention,

Specification of Letters Patent.

Patented July it 1917.

Serial No. 794,567.

showing two pins mounted in the flange formed upon, and as an integral part of, the plate;

Fig. 2 is a plan view on an enlarged scale, the pins being removed;

Fig. 3 is a detail view of one of the washers Fig. t is a horizontal section on the line '-'l l of Fig. 1;

Fig. is a side view of one of the pins removed.

As illustrated in the drawings, the tuning pin, which is formed of metal, is L-shaped in side elevation and includes a stem 10 threaded at one end and having an arm 12 bent at substantially right angles thereto at the other end. The arm 12 preferably has a groove 1a to retain the string 16 which is attached to the tuning pin by coiling it around the lower end of the stem 10 above the arm 12 and passing its end through a hole 18 in said stem. The groove 14 is intended to retain the string on the arm 12 but may be omitted if desired. Whether the groove 1 1 is provided or omitted, the stem 10 is preferably so formed or bent that the string 16 when stressed engages the arm 12 and pulls substantially in alinement with the axis of the threaded portion of the stem 10, so that the arm 12 alone, or with the groove ll, serves as a string guide. The threaded portion of the stem is non-circular, being flattened at opposite sides, as most clearly shown in Fig. 41-, and in factthis cross-section may be, and commonly would be, continued throughout the length of the stem 10 though this is largely a matter of convenience in manufacture. The purpose of flattening the sides of the stem is to permit its being held. against rotation by washers having similarly shaped holes and obviously any other desired cross-section capable of securing the same function might be substituted, though the form suggested is preferred as giving a maximum strength of thread and the greatest ease of manufacture.

As stated, the pins are arranged in pairs, the pins being generally indicated in Fig. 1 by the letters A and B. The stems 10 of the pins pass through round holes 20 in the flange 22 which preferably is formed integrally with the plate. The pin A carries a nut 30 and the pin B a nut 31. Between the nuts 30 and 81 and the flange 22 are a pair of washers 2d and 25. The washers 24: and 25 are identical in form and each has an aperture 26 adapted closely to embrace the stem of one pin and an elongated slot 28 adapted closely to embrace the flattened sides of the adjacent pin, the elongation of the slot being sufiicient to allow for slight variations in the spacing of the holes 20. The washers 2d and are reversely arranged so that the aperture 26 of washer 24 engages the pin A while the aperture 26 of the washer 25 engages the pin B. In this way each of the pins A and B is closely confined by the corresponding washer 24c or 25, and is locked against rotation by the engagement of that Washer with the other pin. It is of course possible to secure similar results with a single washer, but in that case the slot 28 should be somewhat more closely fitted than where two washers are used. The use of two washers is preferred because it produces a rather more stable structure, and for the further reason that where two wash ers are used they can be so adjusted relatively to each other as to center the pins in the holes 20. After the strings are stressed the friction between the two washers will hold the same in adjustment and prevent any creeping when the nuts 30 and 31 are turned, thus preserving the centering of the pins in the holes 20. This cannot be secured when a single washer is used, as one pin would tend to creep in the elongated slot 28.

It will be observed that the construction above outlined brings the stress exerted by the string in direct axial line with the tuning pins and removes any temptation for the tuner to bend the pins in tuning, as is comionly done with the usual form of wrest pin. It also properly locates the stress so that there is no possibility for the pin to yield under the continued pull of the string. The pins may be inexpensively manufactured and the retaining washers may be readily stamped out of plate material. The arrangement permits a very close spacing of the pins and it is possible to set the slots 26 and 28 in the washers parallel and at any desired angle such as that indicated in the drawings so as to cause the arms 12 on the pins to project uniformly in any desired di- Gopies of this patent may be obtained for five cents each, by addressing the rection to secure any desired clearance and spacin Having thus described our invention what we claim is l. The combination of a support having a pair of apertures; a pair of tuning pins extending through said apertures and each including a non-circular threaded stem and string-attaching means; a pair of superposed washers reversely mounted on said pins hearing on said support and each having an aperture closely fitting the non-circular por tion of its corresponding pin and a portion engaging the other pin to hold the first pin against rotation but leaving said other pin free to move transversely relatively to the first pin; and nuts on the stems of said pins and bearing against said washers.

2. The combination of a support having a pair of apertures; a pair of tuning pins extending through said apertures and each including a non-circular threaded stem, string'attaching means and a string-retaining guide substantially alined with the axis of the threaded stem; a pair of superposed washers reversely mounted on said pins, bearing on said support, and each having an aperture closely fitting the non-circular portion of its corresponding pin and a por-.

tion engaging the other pin but leaving it free to move transversely relatively to the first pin; and nuts on the stems of said pins and bearing against said washers.

3. The combination of a support having a pair of apertures; a pair of tuning pins identical in form, extending through said apertures and each including a threaded stem flattened on its opposite sides. and

string-attaching means; a pair of super-' posed washers reversely mounted on said stems, bearing on said support, and each having a pair of parallel slots, one closely fitting a corresponding flattened stem and the other being elongated so as to fit only the flattened sides of the second stem to allow relative transverse movement of the pins; and nuts on the stems of said pins and bearing on said washers.

In testimony whereof we have alfixed our signatures in the presence of two witnesses.

MELVIN- L. SEVERY. WILLIAM L. FLINT. Witnesses:

WILLIAM J. SPERL, EDWARD S. CRocKn'rT.

Commissioner of latents,

Washington, D. C. 

